Double-detonation Models for Type Ia Supernovae: Trigger of Detonation in Companion White Dwarfs and Signatures of Companions’ Stripped-off Materials
Double-detonation Models for Type Ia Supernovae: Trigger of Detonation in Companion White Dwarfs and Signatures of Companions’ Stripped-off Materials
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DOI：
10.3847/1538-4357/ab46b6
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发表时间：
2019-09
期刊：
影响因子：
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通讯作者：
A. Tanikawa;K. Nomoto;N. Nakasato;K. Maeda
中科院分区：
文献类型：
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作者：
A. Tanikawa;K. Nomoto;N. Nakasato;K. Maeda
我们研究了具有不同伴星白矮星 (WD) 的双简并 (DD) 系统中的双爆轰爆炸，通过高分辨率平滑粒子流体动力学 (SPH) 模拟来模拟 Ia 型超新星 (SNe Ia)。我们发现，在某些 DD 系统中，只有主 WD 会爆炸，而主 WD 的爆炸会引起其他 DD 系统中伴随 WD 的爆炸。前一种情况是所谓的动态驱动双简并双爆（D6）爆炸，或氦点燃剧烈并合爆炸。主 WD 的 SN 喷射物从伴生 WD 中剥离材料，其质量为 ∼10−3 M⊙。当伴随 WD 是 He 壳层≲0.04 M⊙ 的碳-氧 (CO) WD 时，剥离的材料含有碳和氧。由于根据 iPTF14atg 的观测推断，D6 爆炸会产生低速喷射物成分，因此 D6 爆炸可以与亚光度 SNe Ia 对应。剥离的材料可能有助于在几个 SNe Ia 中看到低速 C。在后一种情况下，如果伴生 WD 是 He WD，则通过 He 爆轰爆炸；如果它们是带 He 弹的 CO WD，则通过双爆机制爆炸。我们根据爆炸次数将这些爆炸命名为“三重”和“四重”爆炸（TD/QD）。 QD爆炸可能是发光超新星Ia的对应物，例如SN 1991T和SN 1999aa，因为它们产生大量56Ni，并且它们的He爆炸产物有助于伴随这种发光超新星Ia的早期发射。另一方面，TD 爆炸可能无法产生足够数量的 56Ni 来解释发光的 SNe Ia。
We have studied double-detonation explosions in double-degenerate (DD) systems with different companion white dwarfs (WDs) for modeling Type Ia supernovae (SNe Ia) by means of high-resolution smoothed particle hydrodynamics (SPH) simulations. We have found that only the primary WDs explode in some of the DD systems, while the explosions of the primary WDs induce the explosions of the companion WDs in the other DD systems. The former case is a so-called dynamically-driven double-degenerate double-detonation (D6) explosion, or helium-ignited violent merger explosion. The SN ejecta of the primary WDs strip materials from the companion WDs, whose mass is ∼10−3 M⊙. The stripped materials contain carbon and oxygen when the companion WDs are carbon–oxygen (CO) WDs with He shells ≲0.04 M⊙. Since they contribute to low-velocity ejecta components as observationally inferred for iPTF14atg, D6 explosions can be counterparts of subluminous SNe Ia. The stripped materials may contribute to low-velocity C seen in several SNe Ia. In the latter case, the companion WDs explode through He detonation if they are He WDs and through the double-detonation mechanism if they are CO WDs with He shells. We name these explosions “triple” and “quadruple” detonation (TD/QD) explosions after the number of detonations. The QD explosion may be counterparts of luminous SNe Ia, such as SN 1991T and SN 1999aa, since they yield a large amount of 56Ni, and their He-detonation products contribute to the early emissions accompanying such luminous SNe Ia. On the other hand, the TD explosion may not yield a sufficient amount of 56Ni to explain luminous SNe Ia.